Trench back filling and excavating machine



May 4, 1965 w. w. DUNCAN TRENCH BACK FILLING AND EXCAVATING MACHINE Filed Jan. 29, 1962 4 Sheets-Sheet 1 6 0 @QR m I M z w 0 4/ J w v. a v a 7 5 7 I VM g z. M \6 4 W 7 5 4 5 M N Z -5 7 u M M INVENTOR.

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May 4, 1965 w. w. DUNCAN TRENCH BACK FILLING AND EXCAVATING MACHINE Filed Jan, 29, 1962 w 2 Wm M 0m WM m M w M n W M. m 4 M \m m\ y 4, 1965 w. w. DUNCAN 3,181,258

TRENCH BACK FILLING AND EXCAVATING MACHINE Filed Jan. 29, 1962 4 Sheets-Sheet 5 V) N m N) VZ/Z 1 777 GA/EV y 1955 w. w. DUNCAN 3,181,258

TRENCH BACK FILLING AND EXCAVATING MACHINE Filed- Jan. 29, 1962 4 Sheets-Sheet 4 INVENTOR.

United States Patent 0 s,rsr,ass TRENCH RAGE. FELLENG AND uncavnrnso MACHINE William W. Duncan, Rte. ll, Box 9223, Lathrop, (Calif. Filed Kan. 29, W62, Set. No. lltififlfiil 17 Claims. (Cl. 31-144) This invention relates to dirt handling equipment and more particularly to an improved machine for back filling trenches and additionally featuring means for removing refill from trenches after the fill has taken a set and to facilitate repaving the top of the trench to correspond with paving to either side of the trench.

This application is a continuation-in-part of my application for United States Letters Patent Serial No. 50,766, filed August 19, 1960, entitled Trench Excavating and Filling Machine, and now abandoned.

Today there are available many types of trenching devices useful in laying pipe, conduits, sewers and other facilities, the removed dirt being temporarily stored in a spoil pile extending along one side of the open trench. After the work for which the trench has been opened has been completed, it is necessary to return the fill to the trench. Heretofore, various expedients, and equipment techniques have been employed for this purpose but all are subject to certain disadvantages and shortcomings sought to be corrected and remedied by the present invention. For example, it is common practice today to employ bulldozers mounted on tread laying tractors to shove spoil back into the trench. While this mode of re turning the fill is reasonably fast and inexpensive, it is subject to certain objections. Oftentimes, the heavy equipment employed for this purpose breaks down the side walls of the trench and breaks off large chunks of the pavement bordering the trench. Equally serious and costly is the fact that the very large quantities of fill suddenly dumped into the trench are likely to fall onto newly laid tile or pipe shifting this in the trench and causing severe strain if not actual breakage or even collapse of the newly laid ducts. Commonly, such damage is never discovered until the new duct system is placed in use. Very serious and costly damage inevitably results to say nothing of the cost of locating the damage and bringing in equipment to make repairs.

Other shortcomings of prior practices include the fact that the spoil pile becomes compacted during the long period between excavation and refill. As a result, the bulldozer shoves large chunks of compacted spoil into the trench leaving large voids between chunks and making it most difficult to pack the fill uniformly and properly. Dropping of such large heavy chunks or even a large mass of loose fill into the trench can cause serious damage to the side walls of the trench, to duct work laid in the bottom or" the trench, as well as to pipes and other struc tures crossing the trench in the line of fall.

It has been proposed heretofore to use special back filling equipment not subject to the objections just mentioned but these are inferior and objectionable in other respects. Certain of the proposed back filling machines are specially constructed in their entirety or are designed for permanent installation on a propelling tractor or the like. A large investment is involved in building a special purpose machine useful only for back filling purposes, moreover these and the like back fillers customarily employ a common motor for propelling the machine as well as for driving the dirt handling components. For maximum versatility, effectiveness and usefulness, it is desirable to drive the dirt handling components throughout a wide range of speeds depending on operating conditions and it is equally desirable that the tractor itself be operable at times under maximum power output with the dirt handling ice components operating at slow speeds. Such versatility of operation has not been possible or provided for in any prior equipment.

A further serious shortcoming of prior back filling equipment is the lack of appropriate provisions for removing refill from the trench to a predetermined depth to permit repaving the top of the trench flush with the bordering pavement. Desirably, such repaving operations should not be performed until the fill has settled thoroughly following a protracted period allowed for this purpose. The fill removed to accommodate repaving is no longer neces sary and it is therefore advantageous if the fill removal operation includes suitable provision for loading the fill directly into a vehicle for transportation to a place of disposal.

By the present invention, there is provided a specially designed combined back filling machine and fill removal apparatus. The apparatus per se is completely self-contained and includes its own driving motor as well as various brackets and means for demountably attaching the apparatus to any of a wide variety of propelling vehicles commonly available on construction projects. The assorted brackets makes it a simple matter to connect the apparatus to any power vehicle including tractors of various kinds, power scoop shovels, fork lift trucks and the like. For example, the apparatus can be rested in the mouth of a lowered scoop of a power shovel and rigidly connected to supporting equipment for the scoop without need for providing power transmitting connections between the power source for the shovel and the back filling apparatus. After the back lling job has been completed the apparatus is simply detached from the shovel by removing a few bolts restoring this equipment to its normal use with only the back filling unit per se being put aside and supported on temporary legs until again needed for back filling purposes. 7

The apparatus proper makes use of a semi-cylindrical moldboard arranged to have its lower edge supported at various operating heights including close to the bottom of the spoil pile and effective to raise the spoil along the moldboard and into the path of rotating paddles. These paddles are disposed at a suitable angle to advance the fill while breaking it into small pieces for discharge from the end of the moldboard in a uniform finely-divided ream back into the trench. The paddles are adjustable both radially and angularly for most eifective and efiicient operation and the driving motor is connected to the paddle driving shaft at the end thereof remote from the trench thereby isolating the shaft drive connections from the stream of refill. Also featured is a power-adjustable set of supplemental rollers connected with the moldboard and effective to aid in supporting its lower edge at a desired height, a hydraulic cylinder being used to set the wheels and hold them in a selected position.

Another feature of the apparatus is the provision of demountable excavating blades attachable to the moldboard when removing a layer of refill from a trench with the blades projecting downwardly and forwardly from its lower edge for the full width of the trench. These can be set to remove a layer of refill to a desired depth and to elevate it into the path of the lump disintegrating paddles for transfer into an elevator carrying the removed fillinto a truck driving alongside the trench. By this means, refill which has settled can be removed sufficiently to permit repaying the top of the trench flush with the'adjacent pavement, the removed fill being conveyed directly into trucks for transport to a point of disposal.

Accordingly, it is a primary object of the present invention .to provide an improved self-contained, self-powered back filling and excavating apparatus having numerous features and advantages never proposed heretofore.

Another object of the invention is the provision of a back filling apparatus designed for demountable attachment across one end of a self-propelled vehicle and having its own power motor regulatable to operate the back fill apparatus at any desired efficient and effective speed independently of the speed of operation of the propelling vehicle motor.

Another object of the invention is the provision of a back filling machine which can be used additionally to remove refill and convey the removed fill directly into a truck advancing along the trench with the machine proper.

Another object of the invention is the provision of a back filling machine specially designed for mounting on elevating equipment of a self-propelled vehicle and utilizing the elevating equipment of that vehicle to support the back filler at a desired operating height.

Another object of the invention is the provision of back filling apparatus having power-operated adjustable roller supports useful in supporting the moldboard of the back filler at a desired height.

Another object of the invention is the provision of apparatus selectively operable to back fill a trench and to remove a layer of refill therefrom as it is advanced along a trench.

Another object of the invention is the provision of versatile self-powered apparatus designed for speedy connection to and removal from a variety of self-propelled vehicles and useable to back fill a trench safely, effectively and efficiently as well as to remove a top layer of compacted refill from a trench for continuous movement directlyinto a truck.

These and other more specific objects will appear upon reading the following specification and claims and upon considering in connection therewith the attached drawings to which they relate.

Referring now to the drawings in which preferred embodiments of the invention are illustrated.

FIGURE 1 is an end elevational view of one preferred embodiment of the back filling apparatus proper incorporating the features of the present invention and showing one mode of demountably supporting the same in the bucket of a self-propelled power shovel, the view being taken from the dirt discarge end of the back filler;

FIGURE 2 is a front elevational view of the apparatus shown in FIGURE 1 but on a slightly enlarged scale;

FIGURE 3 is a rear elevational view of the apparatus with portions of the upper structure broken away;

FIGURE 4 is a transverse vertical sectional view through the back filling apparatus on a smaller scale and while mounted on the power elevating equipment attached to the forward end of a tread-laying tractor;

FIGURE 5 is a top plan view on a reduced scale showing the apparatus attached to a power shovel of the general type shown in FIGURE 1 and While advancing along a spoil pile to shift the same back into a trench;

FIGURE 6 is a top plan view similar to FIGURE 5 but showing the equipment advancing along a refilled trench to remove a layer of refill, the view showing conveyor means for elevating the removed fill into a truck advancing alongside the equipment;

FIGURE 7 is a fragmentary end elevational view on a slightly enlarged scale taken along line 7-7 on FIG- URE 6, and in part along the center line of the trench;

FIGURE 8 is a fragmentary transverse sectional view through the trench showing the excavating or fill removal blades;

FIGURE 9 is a fragmentary view showing the manner in which the shanks of the fill removal blades may be adjustably anchored to the moldboard; and,

FIGURE 10 is a perspective view of one of the several excavating blades.

Referring more particularly to FIGURES l to 5, there is shown a preferred embodiment of a self-contained back filling apparatus designated generally 10 rigidly attached to the scoop 11, as by bracket means 81, 83 and bolts 80, 84, of a self-propelled power shovel vehicle 12 to which the scoop is attached by power operated elevating linkages 13. Back filling apparatus 10 includes a rigid horizontally arranged main frame 15 composed of suitably-shaped structural steel members secured together as by welding. Securely welded to the underside of frame 15 is a semi-cylindrical moldboard 16 fabricated from sheet steel. Moldboard 16 is reinforced by thick webs and brackets 17 lying generally vertically between the rear side of the moldboard and the underside of main frame 15. The lower frowardly facing edge 19 of the moldboard may be further reinforced by a longitudinally extending plate 20 bolted or otherwise secured in place. Other reinforcing includes a G-shaped channel member 23 (FIGURES 3, 4) extending lengthwise of the rear of the moldboard with its flanges facing the moldboard and welded or otherwise secured thereto. Reinforcing member 23 also serves to support demountable excavating blades in a manner which will be described presently.

Referring more particularly to FIGURE 3, it is pointed out that the rear lower edge of the moldboard is provided with brackets 24 having bolt holes 25 useful in detachably securing apparatus 10 to a propelling vehicle. It will also be observed that the lower edge 26 of brackets 24 lies generally horizontally and flush with the lower edge of the moldboard thereby at times providing skids helpful in supporting the cutting edge of the moldboard flush with the bottom of a spoil pile or flush with the pavement along which a trench has been dug.

Supplementing brackets 24 in supporting apparatus If), there may be provided a pair of broad-rimmed rollers 28 rotatably mounted on the outer ends of links 29 pivotally supported on brackets 30 secured to the rear of the moldboard. Suitable power operating means, such as a hydraulic cylinder 32 having a piston 33, is pivotally connected at 34 to link 29, the upper end of the cylinder being connected to a bracket 35 fixed to the moldboard and operating in known manner to support rollers 28 adjustably. For example the rollers may be adjusted by admitting or exhausting pressurized fluid through a hose connection 37 (FIGURE 1) whereby rollers 28 may be pivoted in a direction to lift or lower the apparatus relative to the ground. If the back filler is being moved along a pavement it is desirable to so support apparatus It) that edge 19 of the moldboard will not dig into or damage the pavement.

Referring now more particularly to FIGURES l, 2 and 4, it is pointed out that the power-operated portion of the back filler includes a noncircular main shaft 40 having its circular ends 41 journaled in pillow blocks 42 rigidly clamped, as by cap screws 43, to the lower ends of downwardly and rearwardly extending rigid bracket arms 45 disposed at the opposite ends of a moldboard and having their upper ends, as here shown, rigidly welded to the main frame, as is indicated at 46 (FIGURE 1), the upper ends of arms 45 are positionedimmediately forwardly of the upper edge 47 of the moldboard.

As is best shown in FIGURES 1 and 4, the lower edge 19 and upper edge 47 of the moldboard lie in a generally diametric plane passing through the axis of shaft 40, this plane being inclined forwardly of a vertical plane through the shaft axis. In consequence, the moldboard is found highly effective in confining the till flowing to the discharge end 48 (FIGURE 2) of the apparatus. Moreover and importantly, the outlet area of the moldboard remains substantially unobstructed to the free flow of dirt. This is due in large measure to the described disposition and inclination of shaft supporting brackets 45. The end of the moldboard opposite outlet end 48 is preferably closed by an end plate 50 (FIGURES 1, 2 and 4) to minimize the risk of injury to workmen as well as safeguarding against dirt being thrown into the drive chain 51 (FIGURE 2) encircling the sprocket wheel fixed to drive shaft 40 and enclosed within a guard housing 52. Chain 51 meshes with a sprocket gear 54 fixed to a main power shaft 55 supported in pillow blocks 56 suitably mounted along frame 15.

Before proceeding to describe the drive means provided for shaft 55 and chain 51, it is desired to point out that main drive shaft 4t? is equipped with a plurality of adjustable dirt digging and propelling paddles having wide fiat blades 6t fixed to the outer ends of tubular shanks 61 by bolts 62. Shanks 61 telescope into tubular brackets 63 and are secured in any radially extended and angularly adjusted position desired by set screws 64. Tubular brackets 63 are here shown as secured in diametrically opposed pairs to shaft ill by clamping bolts 65. As viewed in FIGURES 1 and 4, the paddles are adjusted to be rotated counterclockwise for delivery of fill toward the viewer of the drawing. As will be readily apparent from the drawing, the rotation of the paddles is effective to dig into the spoil pile and to divide the chunks of compacted fill into fine particles while throwing it inwardly toward the moldboard and axially therealong toward outlet 48.

Referring now more particularly to FIGURES 1 and 2, it will be understood that an important feature of the apparatus involves the provision of a motor having substantially as its sole function that of driving the paddleequipped shaft and providing the hydraulic power necessary to adjust rollers 23. As here shown by way of example, this motor comprises an internal combustion engine 7i) rigidly secured in any suitable manner to main frame 15 and having output shaft 71 from the gear reduction and speed control facility 72 coupled by link chain '73 to the main drive sprocket 7d secured to drive shaft 55. The drive chain '73 is enclosed within a removable protective housing 76. The engine fuel tank '77 is secured to the main frame beside the engine. Suitable controls and speed adjusting means for varying the speed of rotation of shaft 40 are not shown but will be understood as of any well known design suitable for the purposes of the described equipment.

FIGURE 4 shows filler fill attached to a tread laying propelling vehicle d of the type usually having a bulldozer blade rigidly connected to its power-controlled pivotally supported pusher arms 36. These arms are provided with a pulley 8'7 and hoisting cable 38 entrained over a pulley $9 supported at the upper end of heavy duty bracket means 96 secured to the vehicle frame. Cable 88 is attached to a power winch operable through the power transmitting connections to raise and lower apparatus it? to suit operating requirements. As here shown, the bulldozer blade has been removed and replaced by the back ller. This is accomplished by bolting brackets of apparatus 10 to the holes at the forward ends of arms as. Desirably, additional bracing links 91 are bolted to brackets 81 and 92 carried by frame 115 and apparatus llll. As shown, the connected rear ends of links @ll carry a roller $4 arranged to roll between the outwardly facing, vertically-arranged webs of a channel member 95 attached to the opposite sides of bulldozer bracket 96.

it will therefore be recognized that with the described arrangement, back filler Elli can be readily adjusted to any desired elevation forwardly of the track laying vehicle 35. it will also be understood that the supporting arms 86 can be pivoted to a position appreciably lower than that shown in FIGURE 4 in order that the forward edge 19 of moldboard 16 can be positioned below the lower surface of the track laying treads 96 of vehicle 85. This is particularly desirable where the back filler is being used to return particularly large spoil piles to a trench. In such cases, the upper half of the spoil pile would be returned first as the propelling vehicle travels along the lower half of the spoil pile. Later and in a second pass, the back filler operates to transfer the lower half of the pile into the trench. The use of the elevating apparatus provided across the end of the bulldozer tractor serves these needs admirably while permitting apparatus 1b to be raised and lowered as desired for the most effective results.

Referring now to FIGURES 6 to 10, back filler 10 is shown while being used to remove the top layer of a refilled trench 10d preparatory to repaving the top of the trench flush with pavement ldll along which the trench extends. For this use of the apparatus, the lower edge of moldboard 16 is fitted with one or more excavating blade units 163 (FIGURE 10), a suitable number of these units being used so that their combined width approXi mates the width of trench flit). Excavator blade units 103 include an arcuate mounting shank ltld rigidly supporting at its lower end a digging blade lltld provided with a transverse shoulder 11%. Although the blades here shown include but a single shoulder 1%, it will be understood that the upper portion of the blade may be provided with several such parallel shoulders. These shoulders are selectively engageable with the lower edge 19 of the moldboard for convenience in mounting blades ill-5 with their lower edges positioned at different levels below the moldboard edge. Alternatively, the upper half of blade 165 may remain smooth, as shown, and filler strips of different widths may be selectively secured in place rearward of the single shoulder 106. in this case, the rear edge of such filler strips abuts edge 19 of the moldboard and provides the highly desirable backing support for the blades. These filler strips can be detachably secured to blades 1&5 by bolts inserted through holes 1637. Additional bolt holes 1433 are useful to bolt the blades to the moldboard using holes in the moldboard not shown but understood as registering with holes 1%.

The rear edge of the upper end of shank llld is pro vided with a series of notches Hi engageable over the edge of a hole ill extending through the horizontal webs of the channehshaped reinforcing member 23 (FIGURE 9) welded to the rear surface of moldboard 16. Holes 111 are sufficiently large as to receive shanks llll lfreely while being adjusted until one of the notches embraces the rear edge of the upper hole llll whereupon shank we is locked securely assembled in this relationship as by driving a wedge keeper 113 into the hole along the forward face of shank 194. Keepers 113 may be pro vided with bent-over upper ends 114 to engage a tool useful in removing the keepers when detaching excavating units 1%. Blades ms of these units may be made in assorted widths to facilitate the assembly of blades having an appropriate combined width to accommodate the particular trench being serviced.

When the apparatus is equipped to remove fill for repaving the trench, the apparatus is preferably provided with an elevating conveyor 115, here shown as of the belt type, and by which fill removed from trench res by blade units we is elevated directly into the body 116 of a truck 117 traveling beside the apparatus as it advances along the trench. The endless belt 113 of conveyor discharges into an inclined chute 1E9 overlying the upper rim of the truck body 116.

Conveyor assembly 115 is rigidly attachable to apparatus 10 as by structural brackets 12% bolted to main frame 15 and suitably connected to the conveyor along its length. Supported by these brackets is a jack shaft 121 carrying pulleys one of which is connected through belting 123 with power shaft 71 of apparatus it) and the other of which drives a belt 124 connected to the upper end of conveyor belt 318.

A member 12% secured to and projecting from the outlet end of moldboard lid serves as a reinforcing support for the lower end of the conveyor as well as means for guiding removed fill onto belt 118. The structures of this bracket are not shown in detail but it will be understood as including a dirt deflector projecting from the discharge end of the moldboard and effective to lift the dirt off pavement 1m onto the lower end of the conveyor belt as the apparatus is advanced along the pavement by propelling vehicle 12. Once the dirt reaches belt 113, it is elevated into chute 119 for gravity fiow therealong into truck body 116.

The mode of operation of the described apparatus will be quite apparent from the foregoing detailed description of its principal components. When used to refill a trench, the apparatus would normally be employed as shown in FIGURE 5. The operator would be seated on propelling vehicle 12 and would manipulate its conventional controls to advance apparatus into spoil pile 130 extending along the side of trench 166. Motor 70 of the back filling apparatus would be operated at a suitable speed adjusted in advance and as found appropriate to break up the spoil dirt. As the apparatus is advanced along pile 13d, paddles rotate into the pile and break it into particles while advancing the dirt axially of moldboard 16 and discharging it in finely divided stream 131 back into trench ran.

Normally, and particularly if the spoil pile is a small or medium-sized one, the lower edge of the moldboard is adjusted to operate at the level of trench 10%), thereby transferring so that all of the spoil is transferred into the trench during a single pass of the apparatus. In refilling larger trenches, more than one pass of the apparatus may be required. In this case, the propelling vehicle 12 advances along the lower half of the spoil pile as apparatus 10 transfers the upper portion into the trench. During subsequent passes successive lower layers of the piles are transferred into the trench until it is completely refilled.

Of importance is the fact that all material is automatically subdivided into fine dirt as it is progressively advanced toward and into the trench. The operator has complete control of the operation at all times to avoid risk of damage to new-laid ducting or refilling the trench with chunks of dirt. When replacing fill over tile pipe or similar conduits likely to become displaced by a large stream of fill, the operator transfers the fill slowly or only the crest portion of the spoil pile or in any other manner deemed suitable under the prevailing conditions necessary to avoid the possibility of the dirt dislodging or damaging the newly laid conduit sections.

If the apparatus is being supported in a shovel 11 of a power shovel type prime mover, the full load of the apparatus may be, and preferably is, shared by the adjustable rollers 28 provided at the opposite ends of moldboard 16. It is pointed out that the flexible fiuid hoses 37 connected to operating cylinders 32 for these rollers are in communication with conventional hydraulic power equipment driven from motor of the back filler. Since such equipment is well known to those skilled in this art the details need not be shown. However, it will be understood that the operation of the control valves for these connections are operable to supply fluid or to vent fluid from the upper ends of cylinders 32 as necessary to adjust the rollers to any desired height. Once the proper adjustment is obtained the valves are closed to lock the fluid in cylinders 32 thereby holding the wheels in adjusted position.

The apparatus shown in FIGURE 4 is used in the same way as that illustrated in FIGURES 1 to 3 and 5. It possesses certain advantages over that shown in FIGURES l to 3 in that the elevating equipment normally employed with bulldozers is of heavier construction and generally more suitable for positioning the back filler either above or below the lower surface of the endless treads 96 of propelling tractor 85.

After the back fill has settled for a period of weeks and has become thoroughly compacted, it is desirable to remove a layer several inches deep in order that the top of the trench may be repaved flush with the pavement along which the trench extends. This is accomplished by attaching the digger blade units lid? to the midportion of lower edge 19 of the moldboard in the manner described in detail above. Once the blades have been secured in place as described, apparatus 16 is advanced along the refilled trench as shown in FIGURE 6. It will be understood that the dirt elevating conveyor would then normally be connected opposite the discharge end of the moldboard and operated to deliver the removed fill into a truck 117 advancing with the apparatus along the trench. As the apparatus advances along the trench, teeth H35 remove the top layer (FIGURE 7) of the refill to a depth of five inches. This layer rises along the surface of plate 195 into the moldboard 16 where it is disintegrated by rotating paddles 60 and immediately transferred into the truck and carried away to a point of disposal as another truck drives up into receiving position opposite chute 119. Accordingly, a single pass of the apparatus along the trench suifices to remove the fill to a predetermined depth and leaves the remainder compacted and undisturbed'in readiness for repaving flush with existing paving it'll.

When the back filler is not in use or mounted on a propelling vehicle, it is easily supported in an upright position on four legs only one of which is illustrated in FIGURE 1. As there shown, the leg comprises a length of heavy duty piping having a base plate 141 welded to one end. The other end has a sliding fit within one of four open-ended tubular sockets 142 welded to the outer corners of frame 15. A ring or other suitable stop 1-4-3 is welded to legs 149 below its socket seating end. This stop limits the axial movement of the legs into the sockets regardless of whether they are inserted into the lower ends of the sockets, as they are when storing the apparatus, or into the upper ends of the sockets as they may be while the back filler is mounted on a vehicle. When supported as shown in FlGURE 1, legs 1% are retained with the equipment in readiness for insertion in the lower ends of the sockets as soon as it is desired to demount the unit from a propelling vehicle.

While the particular trench back filling and excavating machine herein shown and disclosed in detail is fully capable of attaining the objects and providing the advantages hereinbefore stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as defined in the appended claims.

I claim:

1. A self-contained unitary self-powered back filling apparatus designed to be detachably but rigidly and immovably secured temporarily to a motor driven vehicle of the type having primary uses other than the support and transport of said detachable back filling apparatus and without diminishing its utility to perform all of said primary uses, said apparatus having an elongated horizontally disposed main frame and including means carried by said main frame constructed and arranged for quickly attaching said unitary apparatus rigidly and immovably across one end of a motor-driven vehicle and for quickly detaching said apparatus therefrom, a semicylindrical moldboard secured to said main frame and including a closure end wall transversely of one end thereof and an unobstructed outlet for dirt at its second end, a paddle equipped shaft extending along the axis of curvature of said moldboard and having a rigid supporting bracket therefor at said second end which bracket extends downwardly and rearwardly from the forward longitudinal edge of said main frame thereby avoiding obstruction of dirt flow through the rear half of the outlet end of said moldboard, and a driving motor for said back filling apparatus mounted directly on said main frame and coupled to said paddle equipped shaft to drive the same at any desired speed irrespective of the speed of operation of the motor driving the motor vehicle used to transport said back filling apparatus along a trench during back filling of the same.

2. Back filling apparatus as defined in claim 1 characterizcd in the provision on said apparatus of detachable blade units each having a blade and a mounting shank projecting from one edge of the blade, and mounting means carried on the rear side of said moldboard supporting said blade units in edgc-to-edge relation with their blades projecting downwardly and forwardly of the lower edge of said moldboard for a distance therealong approximating the width of a refilled trench and effective to excavate the fill to a predetermined depth as said apparatus is advanced lengthwise of the trench.

3. A back filling apparatus as defined in claim 2 characterized in that mounting means for said blade units comprises a reinforcing member for said moldboard, said reinforcing member extending along and being rigidly secured longitudinally of the moldboard and having openings for receiving and seating the shanks of said blade units.

4 Back filling apparatus as defined in claim 3 characterized in that said reinforcing member includes means seataole in one of a plurality of openings along the length of the shanks of said blade units, and removable means for holding said shanks rigidly locked in any selected one of its several mounting positions depending on the depth to which a refilled trench is to be excavated.

5. Back filling apparatus as defined in claim 1 characterized in the provision of a plurality of attaching facilities, struts and the like, secured to said main frame and to said moldboard and useful selectively in attaching said apparatus temporarily securely and rigidly to any one of a variety of conventional motor-driven vehicles without need for attachments permanently fixed to said motor-driven vehicles adding to the weight of said vehicles and interfering with the utility thereto.

6. Back filling apparatus as defined in claim 5 characterized in that said attaching facilities, struts and the like, include first bracket means carried along the rear walls of said apparatus and connectible t0 the walls of a scoop of a self-propelled dirt-handling power shovel, and second bracket means for securing an upper portion of said apparatus to an upper portion of said scoop all without need for extra fittings fixed to the scoop.

7. Back filling apparatus as defined in claim 6 characterized in that said attaching facilities include bracket means projecting from the rear wall of said moldboard along the lower edge thereof adapted to rest directly on the lower forward edge of a scoop when the same is lowered to lie close to the surface of the ground along the edge of a trench.

8. Apparatus for excavating a predetermined depth of trench refill from below the lip edges of a trench and transferring the excavated dirt into a hauling truck as the said excavating apparatus is advanced along a dirt-filled trench, said excavating apparatus comprising a self-powered unit including a driving motor and having means for easily and quickly detachably securing the same across the forward end of a separately-powered motor vehicle adapted to straddle a trench as the vehicle advances therealong, said unit having moldboard means extending crosswise of the trench with its lower edge supported closely spaced to the pavement surface along either side of the trench and along which a trench has been dug, detachable blade means secured to said unit and projecting downwardly into the trench at an acute angle to the vertical from the lower edge of said moldboard in an area spaced between and inwardly from the opposite ends of the moldboard for approximately the full width of said trench, said detachable blade means being effective to remove a predetermined depth of refill present in said trench and located below the surface of the pavement, power-driven conveyor means carried directly by said unit including rotary paddle means on the forward side of said moldboard operable to tranfscr removed fill to one end of said moldboard, said power-driven conveyor means including endless conveyor means and a driving motor therefor operable to elevate removed fill into a truck advancing along one side of said fill-removing unit.

9. Apparatus as defined in claim 8 characterized in the provision of vertically adjustable roller means movably supported at the opposite ends of said moldboard means and adapted to roll along the pavement to either side of the trench to aid in supporting the lower edge of said moldboard means close to the pavement, and hydraulic cylinder means energized by said self-powered unit connected between said roller support means and said apparatus for adjusting the positions of said rollers and for holding said blade means in position to excavate the trench to said predetermined depth.

10. Apparatus as defined in claim 8 characterized in that said moldboard means includes a plurality of bracket means secured to the rear thereof and including means for facilitating the rigid and immovable attachment of said apparatus selectively to any one of several different types of conventional self-propelled vehicles and operable to advance said apparatus along a trench opening through a pavement.

11. In trench back filling apparatus, that improvement which comprises a semi-cylindrical moldboard having a reinforced straight lower edge adapted to be advanced into a spoil pile closely adjacent the lower ground-contacting surface thereof, the upper edge of said moldboard overlying and projecting forwardly of the axis of curvature of said semi-cylindrical moldboard to confine dirt therewithin while the dirt is being advanced through an outlet at one end thereof, rotating paddle means carried by a shaft mounted coaxially of said moldboard, means supporting the opposite ends of said shaft including rigid bracket means at the dirt outlet end of said moldboard and extending downwardly and rearwardly to said shaft from adjacent the upper forward longitudinal edge of the moldboard, motor means mounted on said apparatus adjacent said moldboard and having as its principal function the rotation of said paddle means as the apparatus is advanced along a trench spoil pile by separate motordriven means, said apparatus including a main frame provided at its opposite ends with open-ended verticallydisposed sockets, and a plurality of legs each having an end selectively insertable in either end of said sockets, said legs being effective when inserted into the lower ends of said sockets to support said apparatus stationarily and in a stable upright position, and said legs being stored in a non-supporting position inserted into the upper ends of said sockets.

12. Apparatus as defined in claim 11 characterized in the provision of a pair of supporting rollers mounted on said moldboard having power-operated adjustable means for varying the position thereof relative to the lower edge of said moldboard and for holding the same immovably in different adjusted positions.

13. In temporary combination with self-propelled vehicle means of general utility other than in combination with back-filling apparatus, a readily detachable completely self-contained, self-powered back-filling apparatus having its own main frame and designed for back filling trenches from a spoil pile extending along the side of the trench, said self-propelled vehicle means being free of attachments and modifications interfering with the full use thereof for its normal purposes when detached from said back-filling apparatus and being so constructed and arranged as to be readily connected to and disconnected from bracket means carried by and forming part of the main frame of said back-filling apparatus, said backfilling apparatus being supported transversely across one end of said self-propelled vehicle means with its dirt discharging end adjacent one lateral side of said vehicle means, said back-filling apparatus having rotary paddle means journalled at its ends in the main frame of said back-filling apparatus and effective upon rotation to transfer dirt from a spoil pile in finely divided form toward and into a trench, semi-cylindrical moldboard means secured to said main frame lengthwise of and behind said rotary paddle means, said moldboard means including a closure end wall transversely of one end thereof and an unobstructed outlet at its other end for channeling the 1 1 flow of dirt from the spoil pile through said other end and into. the trench, independently controllable motors mounted respectively one on said self-propelled vehicle means and one on said back-filling apparatus, one of said motors being controllable to drive said paddle means and the other of said motors being controllable to propel said vehicle means to advance said back-filling apparatus lengthwise of said spoil pile.

14. A fully complete self-contained, self-powered unitary back-filling apparatus having its own main frame designed to be quickly and easily connected temporarily crosswise of one end of heavy-duty, self-propelled vehicle means primarily useable for other purposes and without interfering in any substantial manner with its full efficiency use of said vehicle means for its original primary designed purposes, said back-filling apparatus having means attached to said main frame and so constructed and arranged as to connect the main frame of said apparatus detachably and substantially immovably to said selfpropelled vehicle means, said main frame having rotary dirt-transfer paddle means journalled thereto on a generally horizontal axis extending crosswise of the propelling vehicle selectively operable to shift dirt into and out of a trench while being advanced therealong, motor means mounted on said main frame and connected to drive said paddle means independently of said self-propelled vehicle, moldboard means rigidly secured to said main frame embracing the rear half of said rotary shaft means and having an outlet at one end of said shaft which is free of obstruction in the rear half thereof to avoid interference with the flow of dirt to said outlet from said paddles, and excavating blade means detachably mounted on and extending downwardly from the lower mid-portion edge of said moldboard for excavating backfill from the trench for replacement with permanent pavement materials.

15. Back-filling apparatus as definedv in claim 14 characterized in the provision of vertically adjustable roller support means for said apparatus mounted on said moldboard including power driven means for adjusting the vertical position of said rollers relative to the lower longitudinal edge of said moldboard.

16. Back-filling apparatus as defined in claim 14 characterized in that said excavating blades are mounted in edge-to-edge relation along the lower edge of said moldboard in an area between the opposite ends of said moldboard with their lower edges aligned in a plane spaced below the upper lateral edges of a trench and cooperating to excavate fill to a pre-determined depth and width from a trench along which said apparatus and said blades are being advanced, the removed fill flowing upwardly along said blades and into the path of rotation of said paddles for propulsion thereby to the discharge end of said apparatus.

17. Back-filling apparatus as defined in claim 16 characterized in the provision of elevating means connected for power drive from the motor means driving said paddle equipped shaft means and effective to elevate the removed fill into a truck advancing along said trench with the backfilling apparatus.

References Cited by the Examiner UNITED STATES PATENTS 1,508,716 9/24 Ochs.

1,563,975 12/25 Goeringer 37-144 1,807,489 5/31 Middleton et al. 37-144 1,851,301 3/32 Bunnell 37-45 2,029,122 1/36 Stout.

2,042,196 5/36 Senz 37-145 2,109,393 2/38 Le Bleu 37-43 XR 2,390,286 12/45 Adams 37-45 XR 2,446,074 7/48 Blackmore 37-145 XR 2,488,695 11/49 Upton.

2,698,492 1/55 Justice 37-145 2,714,775 8/155 Crawford 37-144 2,726,463 12/55 Rogers 37-145 XR 2,933,838 4/60 Rockwell.

3,091,873 6/63 West 37-143 ABRAHAM G. STONE, Primary Examiner.

RICHARD A. DOUGLAS, BENJAMIN HERSH, WIL- LIAM A. SMITH III, Examiners. 

1. A SELF-CONTAINED UNITARY SELF-POWERED BACK FILLING APPARATUS DESIGNED TO BE DETACHABLY BUT RIGIDLY AND IMMOVABLY SECURED TEMPORARILY TO A MOTOR DRIVEN VEHICLE OF THE TYPE HAVING PRIMARY USES OTHER THAN THE SUPPORT AND TRANSPORT OF SAID DETACHABLE BACK FILLING APPARATUS AND WITHOUT DIMINISHING ITS UTILITY TO PERFORM ALL OF SAID PRIMARY USES, SAID APPARTUS HAVING AN ELONGATED HORIZONTALLY DISPOSED MAIN FRAME AND INCLUDING MEANS CARRIED BY SAID MAIN FRAME CONSTRUCTED AND ARRANGED FOR QUICKLY ATTACHING SAID UNITARY APPARATUS RIGIDLY AND IMMOVABLY ACROSS ONE END OF A MOTOR-DRIVEN VEHICLE AND FOR QUICKLY DETACHING SAID APPARATUS THEREFROM, A SEMICYLINDRICAL MOLDBOARD SECURED TO SAID MAIN FRAME AND INCLUDING A CLOSURE END WALL TRANSVERSELY OF ONE END THEREOF AND AN UNOBSTRUCTED OUTLET FOR DIRT AT ITS SECOND END, A PADDLE EQUIPPED SHAFT EXTENDING ALONG THE AXIS OF CURVATURE OF SAID MOLDBOARD AND HAVING A RIGID SUPPORTED BRACKET THEREFOR AT SAID SECOND END WHICH BRACKET EXTENDS DOWNWARDLY AND REARWARDLY FROM THE FORWARD LONGITUDINAL EDGE OF SAID MAIN FRAME THEREBY AVOIDING OBSTRUCTION OF DIRT FLOW THROUGH THE REAR HALF OF THE OUTLET END OF SAID MOLDBOARD, AND A DRIVING MOTOR FOR SAID BACK FILLING APPARATUS MOUNTED DIRECTLY ON SAID MAIN FRAME AND COUPLED TO SAID PADDLE EQUIPPED SHAFT TO DRIVE THE SAME AT ANY DESIRED SPEED IRRESPECTIVE OF THE SPEED OF OPERATION OF THE MOTOR DRIVING THE MOTOR VEHICLE USED TO TRANSPORT SAID BACK FILLING APPARATUS ALONG A TRENCH DURING BACK FILLING OF THE SAME. 